Computer based receptogram approach: an objective way of assessing immunohistochemistry of androgen receptor staining and its correlation with hormonal response in metastatic carcinoma of prostate.

AIMS

To categorise the immunostaining heterogeneity of androgen receptors in metastatic carcinoma of the prostate using a pattern oriented approach and to correlate the results with response to hormonal treatment.

METHODS

Paraffin wax embedded tumour sections from 85 patients with metastatic carcinoma of the prostate were processed for immunocytochemistry and stained for the androgen receptor using antiandrogen receptor antibodies. A computer based image analysis system was used to analyse the pattern of nuclear immunostaining in a minimum of 500 nuclei/slide. Depending on the nuclear receptor content and concentration, receptogram patterns were established for each specimen. The receptogram pattern was correlated with clinical response to hormonal treatment.

RESULTS

Clinical response to hormonal treatment was documented using prostate specific antigen as the marker into responders (good, fair, stable) and non-responders. Forty four of 48 patients who responded to hormonal treatment had type 1 (35) or type 3 (nine) receptograms, which are characterised by a unimodal peak or multimodal peaks within a narrow concentration range. Thirteen of the 18 patients who stabilised had type 1 or type 3 receptograms. Seventeen of the 19 patients who did not respond to hormonal treatment had either type 2 or type 4 receptograms, which are characterised by skewed or bimodal androgen receptor distribution. Positive and negative predictive values of receptograms were 96.5% and 63%, respectively.

CONCLUSIONS

Image analysis of androgen receptor immunostaining with a receptogram oriented approach provides important prognostic information that can be used to predict response to hormone treatment in patients with metastatic carcinoma of the prostate.